Telegraph signal translating system and apparatus



L. M. POT-rs 2,327,369

TELEGRAPH SIGNAL TRANSLATING SYSTEM AND APPARATUS Aug. 24, 1943.

Filed Nov. 15, 1940 5 Sheets-Sheet l mOw INVENTOR. LOUIS M. POTTS Aug.24, 1943. L M. POTTS 2,327,359

TELEGRAPH SIGNAL 'I'RANSLATING SYSTEM AND APPARATUS Filed Nov. 15, 19407 5 Sheets-Sheet? INVENTOR. LOUIS M. POTTS ATTORNEY.

Aug. 24, 194-3. M. PoTTs 2,327,369

TELEGRAPH SI GNAL TRANSLATING SYSTEM AND APPARATUS Filed Nov. 15, 1940 5Sheets-Sheet 5 INVENTOR. LOUIS M. POTTS f I42 BY '93 FIG. 6

' ATTORNEY.

5 Sheets-Sheet 4 L. M. POTTS Filed Nov. 15, 1940 TELEGRAPH SIGNALTRANSLA'I'ING SYSTEM ANb APPARATUS POTTS INVENTOR.

A ORNEY.

LOUIS M.

NON. w N. 5383 5.2.35. mmhtimzsmk N N was 222 525. a EN EN |...i :N 1%N3 6N munmoowm Aug. 24, 1943.

I Aug. 24, 1943. PQTTs 2,327,369

TELEGRAPH SIGNAL TRANSLATING SYSTEM AND APPARATUS INVENTOR. LOUIS M. POTTS Flea ATTORNEY.

Patented Aug. 24, 1943 TELEGRAPH SIGNAL TRANSLATING SYSTEDI- ANDAPPARATUS Louis M. Pctts, E va.nstcn, Ill., assigncr to Teletype v.

Corporation, Chicago; Ill a corporation of Delaware 1 AppiicationNovember 15, 1940, Eei'ial No. 365,730

7 I "21Glaims. This invention relates to printing telegraph apparatusand systems and particularly to translating mechanisms for translatingsignal combinations according to one code into signalcombinationsaccording to another code.

An objectof this invention is to make possible the use 'of a keyboardtransmitter operable according to one telegraph code and a-recorderoperable acoordingto a different telegraph code tion to produceselectively apertures between a source of 'light and a scanning cylinderWhich houses a photoelectric cell and which has circurnierentialcombinations of light transmitting and opaque areas according to thefacsimile signaling code. Upon the reception of a permutation codesignal combination-and the setting of the slides k the scanning cylinderis set in rotation for one revolution. Facsimile telegraph signals arethen generated according to the activation of the photoelectric cellunder ning cylinder.

According to another embodiment of the invention the permutation codesignals arereceived by a multiple magnet receiving selector mechanismwhich has a selector magnet corresponding to each element of the code;Each of the selector magnets controls the positioning of one of theslides which co-operatively establish individual apertures for a lightbeam to be scanned by the scanning cylinder. As in the case of the firstmentioned embodiment of the invention, the scanning cylinder is set inrotation for one revolution upon the reception of a permutation codesignal combination by the multiple magnet receiving selector mechanism.

In the practice of the invention a communicatic-n system is featuredwhich includestranslating devices of the single magnet or multiplemagnetcontrolled type whereby intercbmmunication may had betweena subscriberhaving a permutation code transmitter and facsimile recorder and asubscriber having permutation code transmitter the control of the scanand recorder, or between two subscribers having permutation codetransmitters and facsimile recorders. Also featured are communicationsysterms for providing intercom'rn'unication between a centralstation'and a plurality of subordinate stations ando-per'able overrnetallic cc-nductors or radio channels, said communicationsystemsincluding translating devices as hereinbefore described generally and tobe described hereinafter in detailfor translating permutationcodesignals into-facsimile signals. r g V For a complete understanding'oithe invention reference may be had to the following detailed descriptionto be interpreted in the light of the accompanyingdrawings wherein, Fig.l is'a plan view partly broken away showing a signal translating deviceoperable un'denthe control of magnets individual to each impulse of areceived signal combinati n;

Fig. 2 is a perspective viewpartly broken away showing structuraldetails of the signal translating device shown in Fig. 1; V

Fi 3 is an eleVational view of thetranslating device shown in Fig.1; V e

Fig. 4 is a plan view partly broken away showing a modified form ofsignal translating device which operable under the control of a singlereceiving magnet; g

Fig. 5 is anelevaticnal viewpartlybroken away taken at the rig t handside of Fig'. 4;

Fig. 6 is an ele onal view taken at the lower edge of Fig.

Figs. 7 and 8, when placed end to end with.

Fig. 8 at the right of .7, show a complete corrmiunication systemincluding signal translating devices according to the previouslyidentified figures; 7 V

Fig. 9 is a schematic wiring diagram of a communication system includingsignal translating d vices and having a metallic communication channelin one direction and a radio channel in the other direction; and

i 10 is ,a schematic wiring diagram of a communication system similar tothat of Fig. 9 but having metallic channels in both directions.

Referring now to the drawings and particularl y to Figs. 1 to 3,inclusive, the reference numeral IE; indicates generally the signalgenerating mechanism of a photoelectric facsimil trans- 'mitter such asthat shown in applicationserial No.'261,418 filed March 13, B939, by L.M. Potts, which matured Nov. 25, 1941, into Patent No. 2,263,592. Thepatent discloses akeyboard controlled transmitter and keyboard controlis not 'of interest in connectionwith the present invention. However,reference may be had to th patent for a detailed description of thephotoelectric scanning and facsimile signal generating mechanism.

The signal generating mechanism It includes a housing I! into whichextends from one end a rotatable shaft I8. The end of shaft 18 presentedinside cylindrical housing ll supports and has secured thereto by meansof set screw [9 a rotatable canning cylinder 2? A shown in the patent,cylinder 20 has circumferential rows of light transmitting apertures orwindows arranged according to the facsimile code of impulses forletters, figures, and symbols. The opposite ends of scanning cylinder 26and housing cylinder 11 from that where shaft l8 enters is open and thebase of a photoelectric cell 2i is stationarily supported in the openend of the housing cylinder l7. Photoelectric cell 2! is of theelongated cylindrical type and has its cathode and anode at leastcoextensive with the portion of scanning cylinder 2!] which hascircumferential bands of scanning apertures.

At apoint just clear of the surface of scanning cylinder 23 the housingcylinder H is cut away on a verticalplane and to the fiat surfaces.resulting from the cutting away of the portion surfaces provided bycutting away a portion of Retainer. plate 26 is providedthe cylinder ll.7 with light transmitting apertures 21, there being an aperture 21 inalignment with each of the circumferential rows of light transmittingwindows or apertures of rotatably scanning cylinder 20.

The apertures 21 are arranged in two rows in staggered formation inorder to minimize the space required for the full set of apertures.

The slides 24 are movable endwise individually into either of twopositions which may be designated as a marking and spa c ng position.They are provided with apertures 23 arranged in two roWS spacedaccording to the spacing of the rows of apertures 27, and the spacingofthe apertures 28 from each other in each row is such that cer tain ofthe apertures will register with'apertures 2'! when the slide is in themarking position and others will register with apertures 21 when the Thearrangeslide 24 is in spacing position. ment of apertures 21' in all ofthe slides 24 is such that for each permutational setting of .theslideszd an alignment of apertures 28 willregister with one onlyof theapertures 21 in the plates 25.

At the opposite side .of frame 22 from that which supports. aperturedplate 23 there is a longitudinally eXtending slot, 29 across whichisdisposed a plurality of vertically positionedpartitions 3!. The spacingofthepartitions 3i corresponds to the spacing of apertures 21longitudinally of'plate 26 so that the partitions 3i define theentrances of li ht passages which may be. completed through alignment ofapertures 28.in 1slides 24 and through apertures 21. A lamp-.32 having along filament 33 is mounted in close proximity to the slot 29' in'framel22 (Fig. 1) and servesas a source of light to be ment 3-8 isurged by compression spring 39 to move longitudinally of shaft l8 toengage driving element 4| which is sleeved on shaft IS. A g'ear' 42 issecured to driving clutch element 4| and'a motor driven pinion 43 mesheswith and imparts continuous rotation to gear 42 and through it todriving clutch element 4|.

Driven clutch element 38 is normally restrained from engagement withdriving element 4| by clutch throwout lever 44 urged by tension spring46 into the path of clutch-throwout cam 41 associated with flange 48 ofdriven clutch element Sleeve 37 has secured thereto a cam 5| which isengaged by a roller 52 carried by a lever arm 53 which is spring biasedto maintain roller 52 in engagement with cam 5!. When the clutchmechanism is in rest condition the roller 52 is resting upon cam 51 nearthe top of a descending slope thereof, and thusimparts a torque to thecam and thus to sleeve 3'1 and driven clutch element to hold them insuch angular position that clutch throwout-lever 44 pulls driven clutchelement 38 entirely out of engagement with driving element li andrubbing of the teeth of one clutch element upon those of the other isavoided.

Clutch 'throwout lever 44 is provided with a leftwardly extending arm 56which terminates belowand in the path of one arm of a clutch trippinglever 51' pivoted at 58. A downwardly extending arm EiQ-of clutchtripping lever 57 is disposed in thepath of a hooked portion El of alink. 432 which is movable rightwardly to rock clutchtrippinglever 5Tcounterclockwise to effect the, withdrawal of clutch throwout lever 44from engagement with clutch throwout cam 41 whereby compression spring39 may move driven clutch elementiiiinto engagement with driving elementd! to receive rotation therefrom and thus impart rotation to shaft 13-and scanning cylinder 29. Shaft i8 is rotated through one revolutionwhereupon driven clutch element 38 is disengaged from driving element ilby the reengagement ofclutch throwout lever 45 with cam s? and shaft I8and scanning cylinder 23 are brought to rest. The co-operation of link62 with clutch tripping lever 51 is of the nonrepcat species due to thedownward camming of link 6?. as it is moved rightwardly by virtue ofengagementof an upwardly sloping cam portion of anorexic ceiv'e and eachselector magnet :isprovided with a pivoted armature I58- Each ofv -thearmaturcs 68 is provided at its liree end with adjustable abutment screw59 whichv is aligned with the right-hand end of associated-slide H. lSlides which carries cam follower roile'r E52 supports a1 lockingballblade 1B which spans the slides 11 adjacent to the lockingprojections is, H "which arein spacing or rightd'land positions havetheir locking proiections -ill resented to the r ht of locldngbail'blade If, and ti as that are ilresentei their marking or =lei-=lia;nd

ciieir locking proiectio'ns presented position have to the left of thelocking bail blade 3%. 'When shaft i3 begins to rotate, cam 51 lowersarm 53 so that the locking blade 2 6 is presented between those of thelocking projections 1 1 that to theright'oi it and those are tot 1 Thus,the slides il are blocked against movement until near the end ofa cycleof rotation ofshaft 58 when cam 51 lifts arm 53' to lift locking bailbladel't clear or the top of locking projection 7 Each-of the slides l alug T! on th lower edge thereof 3), and disposed in .e'- oi the lugs TIis a bail i3 jioivoted at is.

end of clutch tripping link 62 is pivotally connected. When any of theslides H is moved. to its marking positi'on'by its associated selectormagnet El the lug T? will engage b'ai-i 7-8 and rock the bail incounterclockwise direction, thus he tripping of the clutchcomorising'driven element 53 and drivingelement M. From tliis'i't wil beE1310 are to be energized for any given permutation code signalcombination must be energize-doubstarltielly simultaneously rather thaninsuccession from a receiving distributor. The-reason for this is thatthe first slideli to be operwouid effect tripping of the clutch for drding shaft to iirough the operation of bail link 62, clutch trippinglever 53, and clutch throwout lever 5 and the slides H would be, comelocked by the lowering of locking bail blade 75 before the remainingmarking impulses 1...: he code combination could be received and performtheir selective functions; The translating d vice shown in Figs; 1 to 3,inclusive, particularly eration of the photoelectric permutation code 1The photoelectric scanning and transmitter. facsimile signal generatingmechanrm is identical with that shown in Figs. l to 3, inclusive, andthe same reference characters have been applied thereto. Also, thedriving mechanism for the scanning drum and the combined clutch Bailit'- has a depending arm ill-to which the rl-g'ht-han'-d sent that allof the selector-magnets all teat ported in bracket 36.

; assembly ic-undation a plate 185. 111 a plate m by means of pivotscrew carried with it! by means of rew anti-singing device and lock bailfor the slides which control the .lightvalve slides are identical .withthose heretofore described and lareidentified by the same referencenumerals.

The receiving selector mechanism for controliing the operation of thelightvalve slides 24' is similar to that shown in Patent No. 1,937,376grantedNovember 28, 1933, to W. J. Zenner. The reference numeral 8']designates a mounting plate for the selector mechanism. Aselector-magnet assem-biy comprises a bracket 52, to which is secured bymeans of screws 83 a magnet core 8i .Core 84 has two arms, each of whichsupports a winding 86, which is connected to a telegraph line. At theirouter end, the arms of core 84 terminate in pole faces 81. Bracket 82supports opposed pivot screws 88,

in turn .pivota'l'ly support an armature 'lever 82. Armature lever 89has rigidly secured thereto armature M which is disposed in alignmentwith the pole races 81. The other end of armature lever '89 terminates acam follower portion (notshown), which co-operates with an armaturelever cam '32 included in a receiving :selector cam assembly 3.-Selector cam assemmy 93 is driven from gear" 42 through a sleeve 94,which has a reduced oortionirota'ta'bly sup- "Cam assembly '93 issleeved on sleeve 9'4 and is provided'at its opp-osite ends with discs95. To the right of cam assembly 93 sleeve 34 has disc $9! securedthe-reto, and to the left of cam assembly 93 disc or is "splined onsleeve 94 and is 'slidable thereon. A friction disc resilient material,such as felt; is interposed between the disc and the disc 9.! at theright of receivlr: carnassembly 53, and another friction disc is=interposed between the discs 9'4 and it; at the left of camassemciy 93,the friction] discs idcn'tified byviilhfi .numeral S8, .A com-pres :onspring H3! urges disc 35 rightwardly of sleeve 94 and compressesfriction discs 98;. between t adjacent cs. Discs 323, 52', 8-3 and Qformea iri'c 1 clutch through which rotation be .rted to frontcontimlcusly driven sleeve 94. l I Selectorcem assembly includes stopHi2 which is arranged-to be a r ested released for rotationalternatively un the control of a stop gate Hi" n'cluded in s es- Sto-p-g. .te ass mbly 1M- has asxits pivoted below y slet-e l-ili, W'schsupported by pcstsim moonted on mounting plate El. 1-H,

exile thereto the ed screw 1 !2 which. threadedlv e sic mounting'platelilo; be ed. piv-otally for orien it -t p vot screw ms and may beclamped in sired'position of by 52% and arm Mi 'i'nto Stop is 4 carriedby plate of stop arm by a s mg (no wn). gate 5&3 may be latch-edin blcclrelatioi stop arm iii-2 by shomdcredlatch 1e ver 5 i3 is pivotallymounted on ti of plate and. is'urged by so rig. latching engagement withstoo Latch lever. l-i-ES is rocked once of. compression spring 1 M. tolift its shoulder out; of latching engagement with the stop provided,which indicates that the apparatus is operable in response to the verycommonly employed five unit permutation code. This code affords amaximum thirty-two primary "selective combination. However, as is wellknown, by allotting two or the code combinations to shift and unshiftfunction, the code may be ex valve slide in the embodiment of theinvention shown in Figs l to 6. inclusive, functions exactly the samemanner, as far as the transmission of facsimile combinations isconcerned,

as does the sixth light valve slide in Fi'g'sQQl to 3. The difference isonly in the 'rzi' thokior controlling the sixth light valve slide andthis difierence is that i Figs. 1 to 3, the sixth slide presented in oneor the otherof its two pQsitions in accordance with the presence or absence in a signal combination of animpul set'o operate the sixth magnet,whereas in the em' b'odiment of the inventionshown in Figs. 4110 6,inclusive, the sixth light valve slide is presented in one or the otherof its two positions under the control ofshift and unshift permut'ationcode signal combinations. p I Referring to Fig. 6, it will be noted that'in the lower edge of the foremost of the slide bars I ll controlled bythe bail-shaped levers I4 I two notches are provided. Each of the otheroi t h e five slide bars I47 is notched and the positioning of thenotches on the bars is according to' the permutation code so that whenslide bars I4"! have been positioned under the control of the receivingselector mechanism in accordance with a shift code combination, analignment of notches will result in one position and, when the slidebars Ml have been set in accordance with the unshift code combination, nalignment of notches will result in the other position. Be-

low the slide bars I41, and in" registry with the position in which thealignments of notches may result, are selectable bails I6I and IE2carried by levers I63 and I54, respectively, pivoted at IE5 and IE'irespectively. Each of the levers I63 and I 64 has a downwardly extendingaini and the extremities of the two arms are inter} connected by atension spring I63 which biases lever I63 in counterclockwise directionandl'ever I64 in clockwise direction. The levers I63 a'nd I64 havefingers I69 extending toward, each other and the extremities of thefingers its are dis,- posed under oppositely extending flanges II I;carried by a retracting lever H2, pivoted at I13. Retracting lever I'I2has an arm I14; extending upwardly from the point'of the pivotal mounting, with its extremities disposed in the path of arm lid of lockingbaillever 53.

When cam 5i operates lever 53 to lift look: ing bail I6 out of lockingposition it accom' plishes this by rocking lever 53 clockwise. and armIlt thereof rocks retracting leverIIZ counterclockwise with the resultthat the flanges 'I'II engage fingers or IE3 and I64 and drawv the selectable bails IiiI' and :62 clear of the loiwer edges of the slide barsM1; Thus, the selectable bails IiiI and IE2 are prevented frominterfering with settingeof theslide bars I41 according to receivedsignal combinations. When lookpgp n lever is returns to normalpojsiitior which i's the ex r m counterclockwise po tco es viewed inFig. 6, it permits lever ilz to rotate in, clockwise direction, thisrotatibn being parted l; 'y s pring I 53 operatinglthrough levers Hi3one i i and 7 their op'eosj o ngers open fl e ii .1? s in le he slieleer re r sents neither the shif nor til e lln slliit cert hina'tion,both of the selectable tens :il and IE2 will come to rest against thelower e'dges oi the slide bars I41. However, if either o f th e st tebails flees an e 'se efi fb' were. it will enter the a ignment offnotch'es, thus moving lever IIZ their clockwise 'directionthan it isstove hen neither 'qrt'ne' selectable Hails arrangem nt, of notches.

pair of spaced lugs I83fat upper ed e between which the laterallyextending portion or ant} IQ] of IeverJIS QR is disposed. Similarly,slideISI is provided with sii aced lugs I 811 between which thelaterally extendingportioncf e n I32 or lever "it is disposed. Whenlever Hi3 oo'ou ies its extreme counterclockwise position it's sensingb' i iGI ioai aiig ineht or 'jri ie ii'; ith s ic s i' t hel i i li m' eii of i s a m i essh's e he 1 'en1 i t e mg' ts and'h as snirt'eo' iieel site its left-hand position "whereby the associated light valve Slideis] shifted toexti 'e'ine left-h and bositiori to hlo'ck out light fro mone entire set of circn mierential rows :oi gc'olde apertures cylinder29', s ich set of rows of apertures being those assigned eitheralignment or'oot he in the slides on, the'tr'a 'versely extendingportion of, its 'arm l8 l will have engagedthe righthand bne of the andWillhzivies'hiited slide I51 to its extre right-handpojsition, wh by thesixth liht valveslide will be 'pres'entedin extreme righthand po it otobio ek 'oiit' light rroreh or the circumferential rows of apertureswhich were r i l kedwh ffi es ifi Films n e tr m ef hand position and tounbloek those sets of apertures which were then blocked. V g H 'Levei"I'I2 is biased in counterclockwise di ection by a light tension springI38 so that w locking bail lever 53 is in extreme counterclock wiseposition, as viewed in Fig. 6, and its de'plend ing arm We at theright-handend has re 'e the upper end of lever I'I2,.the right-hand endof lever H2 will be under the control o eoge s' we of levers IE3 an useaecwin ,r oe ise higher than either of those fingers move it, it beingunderstood that spring I58 stronger than s ring its so that spring leawiii control the move-merit of lever I I2.

At the oop'er eno' of the em tale e eig'iieed end or lever :12 a slideI81 is pivotaliy ooflr'ui ted thereto. Slide lfil is 'connected teaseventh light valve sl d 188,. Thus; when lev r [i2 is rocked spondingto that which is employed when char acters are printed by typedelements. Accordingly, no signal is to be transmitted in a cycle ofoperation of scanning cylinder 28 initiated as a result of the receptionof a shift or unshift permutation code combination.

As disclosed in the copending application hereinbefore identified, thescanning cylinder 22 is provided with a light transmitting slot for thegeneration of a start signal located in an area on the periphery of thecylinder which includes no portion of any of the character signaltransmitting code slots. Upon release of the scanning cylinder 22 forthe transmission of any facsimile signal, the starting signal slot firstscans the light beam and causes the photoelectric cell to generate asignal for starting the receiving printer. Since no signal is to betransmitted in response to the shift and unshift permutation codecombinations, it is preferred that the scanning cylinder, which isreleased for rotation in response to the shift and unshift signalcombinations in the same manner as for any other permutation codecombinations, shall not effect the generation'of a start signal, sincethis would set the printer in operation and effect spacing of thereceiving tape without recording anything in the space. The function ofthe slide l8? and its associated light valve slide N38 is to block thelight path in registry with the start signal slot of the scanningcylinder 25 when either of the selectable bails lfil or I62 is in theselected position. The blocking occurs when lever I22 is in extremeclockwise position, thus presenting slide I87 and light valve slide I88in extreme right-hand position. At the points where apertures in thelight valve slides 24 align when the slides are set according to theshift and unshift permutation code signals, there are no circumferentialrows of apertures in the scanning cylinder 20. Thus, light is preventedfrom passing through the alignment of apertures in the light valveslides 24 when the slides are set in accordance with the shift andunshift signals and no impulses are generated in the photoelectric cell,the rotation of the scanning cylinder 29 being merely an idle operationapplying no signals to the telegraph line and, therefore, having noeffect on the receiving printer.

Referring now to Figs. '7 and 8, which, fitted together with Fig. 8placed at the right of Fig. 7, show a complete telegraphic communicationsystem, the reference letters A and B indicate subscribers stations.Subscribers stations A and B are identical and only one will bedescribed in detail, which is the A station. At the subscribers stationa facsimile recorder Edi is connected through the winding of relay 262local to the station A to one end of telegraph line 263, the other ofthe motor 261 is connected directly to one side of a powerline and theother terminal may be connected to the other side of the power linethrough conductor 2228, contact and tongue 229 01 relay 262 andconductor 2| I. Thus, when relay 222 is energized due to thetransmission of facsimile signals from the central oifice over telegraphline 223, the circuit of motorZll] will be closed and facsimile recorder2m will be -driven. Relay 2 32 is preferably of the slcw-to release typeso that its contact tongue will not operate in accordance with facsimilesignalsbut will remain closed during the reception of signals to applysteady current to motor 201.

Station A is provided with a permutation code transmitter 2 2 which maybe connected to a telegraph line 2! 3 through tongue 2M of key 2H5,

Tongue 2!? of key 2l6 completes the circuit for motor 207 which drivespermutation code trans mitter 2i2 as well as facsimile recorder 20!.

The other end of telegraph line 213 is connected to one end of onewinding-of a differential relay 218 and this winding will be describedfor the sake of convenience as the upper winding. The other end of theupper Winding of relay 218 is connected to tongue 2H of a relay 22l. Therelays 2i8 and 22! are located at the central station. When the systemis idle, relay 22! is deenergized and its contact tongu 219 engages itsback contact which is connected to one end of battery 222, the other endof which is connected to ground. Battery 222 supplies power forenergizing the upper winding relay 2l8 upon the closure of key 2H5 atsubscribers station A. Key 2 Iii is closed manually when the subscriberdesiresv to operate permutation code transmitter 212 to. transmit amessage.

Upon the energization of the upper winding of; relay 2H3, its tongue 223which is connected to ground is brought into engagement with its frontcontact which is connected to one end of the winding of relay 225, theother end of which is connected to outer tongue 228 of relay 22L Tongue226 normally engages a back contact which is connected to a groundedbattery 221.

Upon the closure of energizing circuit for relay end of which isconnected to tip contact spring I 224 of answering jack 286 at a centralofiice.

At th station A, a motor 26"! is provided for driving the facsimilerecorder 29!. One terminal 225 at tongue of relay 2|8, relay 224attracts its contact tongue 228 which engages its front contact "andcompletes a circuit for lamp 229 from battery 23L Lamp 229 is associatedwith jack 256 and indicates to an operator at the central office thatthe subscriber at station A desires to transmit a message. The answeringoperator thereupon inserts plug 232 into jack 286. It will be understoodthat the operator could answer station B by inserting the sam plug 232into the jack associated with station ".8 had the subscriber at stationE closed his key l2l6 to effect the illumination of his jack lamp [229.

Upon the insertion of plug 232 into jack 206, plug tip 233 engages tipspring 2554, outer ring 234 engages ring contact spring 236 of jack 206,inner ring 23'! engages ring contact spring 238 of jack 2%, and sleeve229 engages bushing 2 H of 'jack 2%.

The bushing 22! of jack 208 is connected to one end of the winding ofrelay 22!, theother end of which is connected to ground. Sleeve 2320fthe plug, which engages bushing 24], is connected by a conductor'2 i2 toone end of the Winding 243,

the other end of which is connected-to one terminal of a groundedbattery 244. Thus, upon the insertion of plug 232 into jack 263, relays22I and 223 are energized in series.

Relay 22 l attracts its contact'tongue 2l9 frompengage'ment with backcontact to" engagementswith front contact,

attracts contact tongue 22% out of engagement with its back contact,thus interrupting the circuit for jack lamp controllingrelay .224, andattracts: its contact tongue 245 into engagement with-a front contact;Contact tongue 2 15, upon engagingits front contact, completes, theenergizing circuit for the lower Winding of 218 which neutralizes theeffect of the upper winding and releases contact tongue 228. l

A further eifect of theenergization of relay 22| is that permutationcode transmitter H2 is disconnected irom battery 222 and isconnectedinstead to outer ring contact spring 238 or" jack286.

Since contact spring 236 is engaged by the outer ring 234 of plug 232,the circuit of, the permutation code transmitter is extended to theoperators cord circuit. This circuit includes 001 ductor 245, winding ofrelay 247, key 255, cone ductor i, winding of repeater relay 252,contact tongue 253 of repeater relays 254 and 256, front contact withwhich tongue 253 is normally engaged since relay 252 is normallyenergized, and

grounded battery 251.

Key 255 normally connects conductor 25! directly to the winding of relay24! and holds relay 258 energized to complete a circuit from groundedlocal holding battery through operators keyboard transmitter 248 andpermutation code printer magnet 229 to ground. Upon the operation of key255, the circuit of relay 258 is opened so thatthe relay releases itsarmatures and thus disconnects transmitter 248 and printer magnet 2%from the local holding battery. In make-beiore-break manner with respectto the circuit of relay 241, the key 255, when operated, also connectstransmitter 228 and printer magnet 2 59 in series with relay 24'! andwith the repeater to which conductor 25! extends. With this arrangementthe operator may cut the transmitter 248 and 2:32 into the permutationcode communication circuit for setting up cir-- cuits desired. bysubscribers or for monitoring message transmission. Under normalconditions, when plug 232 is not inserted into any jack, the groundconnection for maintaining holding current upon relay 252 of therepeater is obtained through the outer left-hand contact tongue 259 of arelay 252. lhis holding circuit includes the winding of relay 26?, whichas will presently appear, controls the operation of a translatormechanism, such as that shown in Figs. etc 6, inclusive. Upon theenergization of relays 22 and 252 the ground connection at thesubscribers permutation code transmitter is substituted for the groundconnection at the contact tongue 250 of relay 262 so thatpermutationcode signal transmission is initiated and the transmitter 2i2 will correspondingly energize and de-er'lergize relay 2M, operatorsreceiving magnet 2 and repeater relay 252. I

. In addition to the tongue 223, differential relay 2l3 has contacttongue 225 connected to ground and engageable with aback contact whenneither or both of windings of relay 2H3 are energized. The back contactis connected byconductor 239 to the jack spring 238 which is engaged byinner ring 23'! of plug 232 from which conductor 2% extends to one endof the winding of relay 262,'the other end of which is connected tobattery 283. An energizing circuit for relay 262 is completed when bothwindings of relay 2i8 become energized and neutralize it to cause therelease of tongue 225, and the relay 262 attracts its two left-hand andtwo right-hand tongues. The outer right-hand contact tongue 264 of relay252 normally engages its backcontact, to which is connected one pole ofbattery 266, the other pole being connected to ground. The contacttongue 26:! is connected by conductor 25l-to one end of the winding ofmagnet 263, the other end of which is connected to ground. The brokenlined rectangle in the upper righthand corner of Fig. 7, designated 21B,is intended to represent diagrammatically a signal translating mechanismsuch as that shown in Figsxe to' 6, inclusive, for translating fro-inpermutation code signals into facsimile signals. Ehe magnet 268corresponds to the signal receiving selector.

magnet 86 of Figs..4 to 6, inclusive. Magnet 258 is normallyhelcl'energized by current supplied from battery 2%. tion of relay 252,contact tongue 254 moves into engagement with its front contact which isconnected to the contact tongue 269 of relay 241. The front contact withwhich contact tongue 259 is engageable is connected to a grounded batetery 2'. Since in a static condition with the -operators set renderedoperative through the actuation of key 2555 relay 2%? is continuously.energized, it being included in the holding circuit for operatorsreceiving magnet 24d, whether the holding circuit be extended from theground 'at 1 the contact tongue 252 of relay 252 or from the ground atthe permutation code transmitter 02 a subscribersstation, battery 2?!will be connected to the front contact of contact tongue 254 of relay262 through contact tongue 259 of relay 241. From this itwill beapparent that receiving selector magnet 26% is not responsive tooscillation of tongue 2% of relay fi'i'iexcept when relay 262 isenergized t:- conne'ct magnet to the tongue 259 through contact tongue.Upon the energization of relay its inner right-hand tongue 2'52 engagesits front contact which is connected to conductor 255 and therefore 'isconnected to the same ground as the winding of relay 2 52; Contacttongue 2'52 of re- 1 lay 282 is connected to one end of one of the.

windings of a double wound relay 213, the other end of which isconnected. to grounded'battery 214. Relay 223 is thus energized inparallel with relay 262, the circuit for the former extending throughone of the contact tongues of'the'latter however, and the energizingcircuit of both includes the retracted contact tongue 225 of relay2l8.

The inner left-hand contact tongue 276 of re v lay 262 normally engagesa back contact which is connected to the front contact associated withthe right-hand contact tongue 21! of relay 213; When contacttongue 276is attracted into engagement with its front contact, a connection isestablished from ground to a. conductor 218 at tently'or, in otherwords, will flash for directing the attention of the operator to aparticular 012-- crating condition. When contact tongue engages itsfront contact, lamp 219- will be illu- However, upon the energize-1 7When contact tongue K to the tip 233 of plug 232.

minated steadily. The left-hand contact tongue 282 of relay 223completes a locking circuit through the left-hand winding of that relay,said circuit also including contact tongue 283 of relay 243 and normallyclosed key 285.

Considering now the operation of the portion of the system in Fig. '7thus far described, upon the closure of key 2i6-by subscriber A, themotor 20! for driving his transmitter 2E2 will be operated and thetransmitter 252 will be connected to battery 222 at the central officethrough one of the windings of relay 218. Relay 2i8 will be energizedand will disconnect ground from conductor 230 and close the circuit ofrelay 22'to connect battery 23! to lamp 223 which will becomeilluminated to indicate to the operator in charge of transmitter 248 andreceiving printer 229 at the central ofi'ice that subscriber A desiresto transmit a message. The operator thereupon inserts plug 232 into jack2% and actuates key 255 placing the operators set in a circuit withrelay 24'1. Relays 22! and 223 thus become energized in series tocomplete the energizing circuit for the second winding of M3, to openthe energizing circuit for relay 22 i, and to connect transmitter 2i2through the upper winding of relay H8 in series with relay 2%! and thusto .op-

erate receiver 239 and interrupt the connection to battery 222, thesebeing the functions of relay 22!. Relay 243 prepares the locking circuitfor relay 213. I

Relay 2i8 being a differential relay which is in neutral condition whenboth windings are en ergized, releases its contact tongues, the lower ofwhich has no immediate effect as the circuit of relay 22E is alreadyopened at contact 228. The release of the upper contact tongue 22%resuits in the connection of ground to conductor 26L whereby relay 262becomes energized. The relay 262 operates to remove the local groundconnection at contact tongue 250 from relay 2%, thus placing the relayunder the control of transmitter H2 and subscribers station A, tocomplete a circuit for the steady illumination of lamp 219; to place thereceiving selector magnet 268 in the translator mechanism under thecontrol of relay 24! and to complete the energizing circuit for relay213. The relay 2T3 upon being energized completes its own holdingcircuit and prepares for the flashing of lamp 219 by making connectionto the sourceof interrupted current,

The circuits are now completed for subscriber A to communicate to theoperator at the central oifice the identity of the connection which hewishes and the operator answers subscriber A by operating transmitter228. The characteristic answer will be recorded on the printer represented by the receiving magnet 259 and will'be repeated by the relay 247to actuate correspondingly the receiving selector magnet of thetranslator mechanism.

The translator device, such as that shown in Figs. 4 to 6, inclusive, isrepresented schemati cally by the selector magnet 258 and thephotoelectric cell 286. The photoelectric cell 296 is connected to thecontrol grid of the first electron tube of an amplifier shownschematically and in dicated generally by the reference numeral 281. Theplate electrode of the last electron tube of the amplifier 231 isconnected by conductor 283 Thus, ignals originating at the subscriberstransmitter 2E2 or at the operators transmitter 248 are received notonly by the operators receiving device 249 but also by the receivingmechanism 268 of the translatorunit and are therein translated intofacsimile signals which are impressed upon the conductor 288 and aretransmitted through plug tip 233 and plug tip contact spring 204 of jack206 to facsimile recorder 20! by way of telegraph line 203 and windingof relay 202, which is energized by the facsimile signals but has nodirect eif'ect since the motor'circuit has previously been closed bycontact pring 2 !'i of key 2H5.

When the subscriber A has informed the op erator at the central officeby means of permutation code signals, the identity of the station withwhich he desires to communicate, which information is recorded by theoperators permutation code printer as a typed message and by thesubscribers facsimile recorder as a facsimile message, the operator thenmakes the connection to the called subscriber. This is done by means ofthe cord plug 29!. The tip 292 of plug 29! is connected to conductor 238in the same manner as tip 233 of plug 232 so that facsimile signals willbe available at that element of the plug. The outer ring 293 of plug 29!is connected by conductors 29 i and 296 to the winding of repeater relay25d and then through the armature 29'! of repeater relay 252'to battery298.

The inner ring 299 of plug 29! is connected by conductor 30! to one endof the winding of supervisory circuit relay 302. The other end of thewinding of relay 302 is connected to grounded battery 303. The left-handcontact tongue 304 of relay 302 is connected to one end of one of thewindings of a double wound relay 366 and the other end of the winding ofthe relay 306 is connected to grounded battery 30?. The inner righthandcontact tongue 303 of relay 362 is connected to one of the terminals oflamp 309, the other terminal of which is connected to grounded battery3! l. Contact tongue 303 of relay 302 is operable between a frontcontact which is connected to ground and a back contact which isconnected to the front contact engageable by the left-handcontacttonguejiZof relay 306. The contact 350 of relay 302 is connectedto conductor 30!, whereby the circuit of conductor 30! may be extendednot only to the Winding of relay 302 to battery 303 but also through theleft-hand winding of relay 306 to battery 3M. As will presently Iappear, inner ring 299 of plug 23! which is connected to conductor 30!is engageable with a jack contact spring which is connected to ground sothat relays 322 and 303 will be energized upon insertion of plug 29!into a jack. The outer right-hand contact tongue 305 of relay302 isconnected to conductor 230 and its back contact is connected to ground,these connections being comparable withthose of contact tongue 250 andits back contact. Relay 302 corresponds in func tion to relay 262 andrelay corresponds in function to relay 273.

The contact tongue MS of relay 3% is connected to a source ofinterrupted current indiholding winding of relay 3&5, the other end ofwhich is connected to grounded battery 361. The contact tongue til ofrelay 3th is connected to a key 368 which may be operated manually tointerrupt the holding circuit of relay 33%. Relay 325 has one end of itswinding connected to the sleeve 32I of plug 29! and the other end connected to battery 32". Relay 3I6 corresponds to relay Its purpose is toprepare a holding circuit for relay The plug 29! serves as means forconnecting a subscriber, such as A, to whatever station to which he mayoesire to transmit a message. For example, he may desire to transmit amessage to subscrihens station which is identical with his own station.This is accomplished by inserting plug as: into jack i286 atsubscribersstation B. Upon the insertion of plug 22H intojack i205, plugtip 2st connects the output 238 of translator ElS to the tip spring I264of jack I285 which is connected by conductor through relay toi'acsirnile recorder lEdl at station B. As soon as 'nipulses begin to betransmitted over telegraph line relay becomes en zed to close itscontact 52rd, thus completthe circuit of operatingmotor lZt'i which isin operation to drive facsimile recorder EZEI. or plug 295 contacts-withbushing oil, wherecy relays tit and I22! series. The insertion ofv plugalso results in the connection to the back contact f relay l2l3 g ofplug ZQiand ring conf acl: 52% and the connection 1 of permutation codeits extension 294 l5 ring contact springfilia a of jack I266 'he upperfront contact of relay Ifll. Relays d lEEl, upon becoming energized,attract everal contact tongues. Contact tongue relay 322i becomesdisconnected from tery i222 and engages its front contact,therecnnectedto permutation code sigconductor c .i" renti ay iiliil to the'key 2H3 ofsubhers eta-non B which is open, so that the er wind ng of relay lflliidoes not become energized. The attraction of the two lowcrcontact rinsof rclaylilfil as the relay becomes en results the closureof the circuitof winding of relay i8 and the disconofbattery from the winding of relaySin only the lower winding of differencontact tongue 3 tc-connect groundto the winding of elay 3-. However, since battery from that relay by the"nest contact tongue of relay l22l the relay .1; not become w ergized anlamp i229 will not become illuminated.

The energizatlon of only one winding of relay .7 attraction 0 itscontact tongues results f in the disconnection of ground from jackspring a and thus from ti e winding of relay 392 at tral office.Thua'the relay 35E, whether it may have been momentarily energized clu;Edi was inserted into jack 52%, re-

' 'ng the time the connection ity itwill have become eniy because relayIEEB is of o-operate variet and its circuit'does become closed untilrelay 522i has become gized which operation occurs substantiallyinstantaneously upon the insertion of the. plug The circuit of conductorrcay i is en zed, the relay will attract into the jack. Relay 3&2 alsooperates substantially instantaneously and attracts its contact tongue3% to complete the energizing circuit for relay 3G6, therebyestablishing contact with the source 3I3 of intermittent current forlamp 389 and also preparing the circuit of a the holding Winding ofrelay 3%. Since relay 355 became energized in series with relay l22i,its contact tongue 3I'I has been attracted to complete the holdingcircuit for relay 3% and that relay remains energized.

Lamp 359 will be illuminated steadily during the transient interval thatrelay 352 remains energized due to the connection of the lamp togroundthrough contact tongue When relay I2l8 opens the energizing circmtof relay 392 and also of the relay 3%, lamp 3519 will be transferred toconnection with the source 3l3 of in- 29I remains in jacks I255 andsubscribers station B is conditioned for Message reception. T -econnection to the source 1H3 of interrupted current is maintained by theholding winding of re-' lay 3% after the operating winding of that relaybecomes ole-energized.

The apparatus is now conditioned for the transmission of messagematerial from subsc ibers station A to subscribers station B and theoperator may actuate key 255 to remove the operators set from thecommunication circuit.

, The permutation code signals generated by the transmitter 2 I2 will berepeated by the relay 24! to actuate the selector magnet 258 of thefacsimiletranslator 215 and the facsimile signals generated in thephotoelectric cell 256 and amplified inthe vacuum tube amplifier 231will appear at the outputcircuit 288 of the amplifier and willbeimpressed upon plug tip 292, jack spring I204, and telegraph line ISlit-3 to operate facsimile recorder I201 at subscribers station 23. Thefacsimile signals, in reaching the recorder I 25H, traverse the relay22M and this relay is preferably slow to release in order that thecontact I209 shall not be openedand closed corresponding to thefacsimile signals to interrupt the circuit of motor I201.

When the subscriber at station A has com- 'pleted the transmission ofhis message, it is only necessary for him to open key ZIS. This opensthe circuit of the upper winding of relay 2!!! which isthe signalingcircuit and includes relay 247 and repeater relay 252, all of whichbecome de-energized. The contact tongues of relay 218 are, therefore,attracted due to the rclays becoming unbalanced and although theattraction of contact tongue 223 has no immediate effect, since thecircuit of relay 226 is interrupted at contact tongue 226 of relay 22!,the attraction of the other contact 225 results in the de-energizationof relay 262 whereby lamp 2'55! is connected to the source ofinterrupted current RI and flashes until plug 232 is removed from jack2%. The. operator should also remove plug as: from jack I206, whereuponall of the relays in the supervisory circuit will become tie-energized.

However, if at any time before the subscriber A releases key 2H3, thesubscriber at station B desires to transmit a reply he will close hiskey I2 It, thus completing the permutation code communication circuitfrom his station through the upper winding of relay I218, which willbecome neutralized and will release its contact tongues I223 and I225,completing the circuit of relay -3U2 to cause it to attract its'contacttongue 398 and-switch-lamp 389 from condition of intermittentillumination to condition of steady illumination, This will indicate tothe operator at the central station that plug 235 should not be removedom jack but that'the connectionto subscrmefs station B should bemaintained to permit the subscriber to transmit a reply to subscribersstation A. It is to be noted that with the plugs 23! in service in thejacks as efo e identified, the closure of keys 2E5 result in thedisconnection ofthe from the windings "of repeater r respectively, dueto the energization or the :elays and 352, respectively, and extension.of the circuit to the respective subscribers. Since the subscribersstation B is identical with subscribersstation A, the station B mayinitiate communication with station A in the am we man e that station Ainit ates communication with station 73; as previously described. In 1is case the operator at the central station will answer the call ofstation B by inserting plug into jack and by operating key 255 to placetransmitter 2 38 and receiving magnet 2- .8 in connnunication station .Eand will complete the call by inserting plug 22! into jack Provisionmade within the contemplat-i n of the invention for the initiation ofcommunication by station A or B with subscrib-- ers whose stationsinclude permutation code apparatus only, and such stations may initiatecommunication with the station A orB.

local ground lays 252 and At the extreme right-hand of Fig. '7 is showna jack 335 which is included in the section of the central offi epreviously described and which has its outer plug contact springconnected by an oifice trunk 333 to the plug tip contact ofthree-circuit jack 335. The in ner plug ring contact spring 33?of'jack'33! is connected to ground and the bushing 333 of jack 33! isconnected to one end of the winding of a relay-3i. the other of which isconnected to ground.

The contact tongue 5 which is operated by relay engageable with a frontcontact which. is connected to ground and is connected by conductor to alamp 333 associated with jack in the section of the central ofice whichhandles the switching of permutation code telegraph only and is shown inFig. 8. The plug tipcontact spring of jack 33! is left unconnectedbecause there is no occasion to trans mit facsimile signals into thesection of the central cfiice which handles permutation code messagesonly.

Upon the the permutation. extended t trunk to spri of relay is e t toground to cause relays 352 t of plug 28! into jack 3 code si alingconductor 2 332 and offi e The circuit 336 to become energized, theformer to disconnect the local ground from perinute code signalingconductor and the latter to prepare its own holding circuit and also thecircuit for supply ing interrupted current to lamp 383. As a result ofthe engagement plug sleeve 32! wi .1 jack bushing 338 the relay 333 isenergized in series with the relay the former to complete the circuitfor lamp 333 associated with jack 33 5 in the permutation. code messageswitching section of the central office'and thelatter to complete theholding circuit for the relay 386.

When lamp 3 93 becomes illuminated the operator in charge of the sectionof the central ofiice,

shown in Fig.8, inserts plug 3-5! into jack 336 preparatory to answeringthe call indicated by lamp 333 for the purpose of completing thecommunication channel. Plug 35! is a three-circuit plug having tip 352,rin 353, and sleeve 354.

In addition to the plug tip contact spring 334, jack 336 is providedwith ring contact spring 346 and bushing 33?. Spring 3 38 is connectedto ground and sleeve 34'! is connected to one end of the winding of alamp controlling relay 356, the other end of which is connected toground. The contact tongue 3-5! associated with relay 355 is engageablewith a grounded front contact and is connected by conductor 358 to oneof the terminals of a lamp 359 associated with jack 33L The otherterminal of the lamp is connected to a grounded battery i The tip 352 ofplug 35! is connected through an operators set 3% which may be identicalwith the operators set in Fig. '7 which, as previously described,consists of transmitter 248 and receiving printer 23E controlled by key255, to one of therelays 332 of a telegraph repeater 363 and through therelay 352 and the contact tongue 353 of relay 365 to ground. The plugtip 352 is also connected by conductor 33! to the back contact of arelay The left-hand contact tongue 3&9, winch is engageable with theback contact, is connected to a grounded battery 31!. The winding ofrelay 338 has one end connected to battery 312 and the other endconnected to sleeve 354 of plug 35! in the same manner that the windingof relay (H3 is connected to sleeve 325 of plug 23!. The purpose ofrelay 363 is to disconnect from the operators set 36! and from the relay332 of repeater 353 the local battery 31% which holds the operator'sreceiving printer and repeater relay 362 energized when plug 35! is notin active service in a jack. The relay 368 also prepares a lockingcircuit for a double wound relay, as will presently appear.

The ring 353 of plug 35! i connected to one end of the winding of arelay 373, the other end of which is connected to grounded battery 3.The contact tongue 376 is connected to one terminal of a lamp 318, theother terminal of which is connected to grounded battery 31?). The frontcontact with which contact tongue 313 is engageable is connected toground and the back contact is connected'to one of the front contacts ofa double wound relay 38 l which has been previously mentioned. Whenrelay 373 is energr'ed, which condition obtains as long as plug 35!remains inserted in jack 335 whereby plug ring 353 engages grounded jackspring 343, contact tongue 316 will engage the grounded front contact tocomplete the circuit of lamp 378 whereby the lamp will be steadililluminated. The front contact with which contact tongue 31'! isengageable is also connected to plug ring 353 and receives groundconnection when the plug is inserted into jack 3H5. Contact tongue 31!is connected to one end of the operating winding of relay 38!, the otherend of which is connected to grounded battery 332. Thus, when relay 313is energized, relay 38! is energized in parallel with it.

lfhe relay 38! is provided with two contact tongues identified by thereference numerals 383 and Contact tongue 383 i connected to a frontcontact of relay 338 which is engageable by a contact tongue 386. Thecontact tongue 333 is connected through a normally closed key 387 toground.

The front contact with which contact tongue 383 of relay 38! isengageable is connected to one different y 381 are completed at thecontacts of jack 33 and V plug 35L all of the relays become energizedupon insertion of the plug into the jack andbecome de-energized uponwithdrawal of the plug from the jack. The holding circuit of relay '38!may be interrupted by the opening of the manually operable key 38'! butthis will have no effect upon the relay 38! and it will remain energizedthrough its operating winding, since when the relay see is energized sothat the holding circuit oi" relay 3 31' is completed. through thecontact tongue 386, the relays 313 and Sci are also energized, thelatter through its operating winding. Also, it is not possible for thesource of interrupted current 388 to be connected to lamp 3'18 when plug35! is inserted into jack 335.. The circuit conditions necessary forlamp 318 to be operated from source of interrupted current 388 are thatrelay 3%! be energize-d through its holdirrg circuit and relay 313 bede-energized to permit its contact tongue 315 to engage the backcontact. When plug 35! is used in establishing connection between twosubscriber stations having permutation code apparatus only, therel'ays358, 373 and 381' and the lamp 3'58 are operable as will be describedlater.

p mutation. code communication circuit site side of repeater 53 fromthat to c "ators set 35! is connected extends ground through the contacttongue 33! of relay and through the winding of relay 3% to the tip of aplug. 3%. Associated with the plug EQB is a supervisory system that isidentical L The with the supervisory system associated with the .n s

ti'on of a double wound relay 3%. The relay 388 energizable in parallelwith the relay 3% and like the relay 3 3i is arranged to prepare acircuit from source of intermittent current 399to lamp 39.1. The relayalso completes its. own holding circuitwhich is prepared by a relay Mil,the circuit of which extends from the sleeve of p u 393. The relay it!also has a contact tongue which normally engages back contact to connectbattery to plug tip 355. and thus-to the winding of repeater relay tohold the repeater relay energized when plug is not use.

Plug is adapted to co-operate. with the subscribers jack il i by whichconnection may be made to a subscribers station, such as the staticn C.Between the subscribers jack 5! l and the i 'subscribers station C,certain supervis ry circuits are needed which will now be described.

Plug tip contact spring 452 of the jack All is connected to the frontcontact of a relay 3 which corresponds to the relay 22! of Fig.7. Therela tit has one end of its winding connected to ground and theother'en'd of the winding connected to the jackbushing did, so thatwhenplug 3t3 s inserted into 'jack 4, relay M3 becomes energized. in serieswith relay 4G I. Conto control the continuous or vintermit-.

tact tongueflfi of relay M3 normally engages'the back contact which isconnected to grounded battery 41?. Contact tongue 4H3 of relay M3 isconnected. to one terminal of one of the windings of the difierentialrelay 618-, the other terminal of which is connected to conductorMflwhich is one of: a. pair of conductors forming a metallic circuitfor. communication between subscribers station C and the central ofiiceat the-station C the conductor M9 is connected to one of the stationarycontacts 42! of. a key 422 which is open when station C is idle.

The other winding of diiferentialrelay 428 has one end connected togrounded battery 423. The other end of the: second winding ofdifferential relay M8 is connected to a front contact of relay 413 withwhich: contact tongue 42 co-operates. Gontact tongue 424' is connectedto a conductor 426 which is the other one of the'pair forming thecommunication circuit between subscribers station C and. the centraloiiice. 'At the subscribers end of conductor. 528 the conductor isconnected toone endof the winding of t .e receiving selector magnet 42'!of a receiving printer. The other end of the winding of magnet 42? isconnectedlthrough transmitter new a movable contactmembcr 429 of key422. When subscribers station Cis idle, movable contact 429 of key 422engages a fixed contact i3l which is connected to ground.

The back contact with which contact tongue 424 of relay M3 co-operatesis connected to ground so that when relay M3 is de-energizerl and key422 is open; the conductive path comprising Contact tongue e24, liceconductor 425, receiving selector magnet 32?, transmitter 522, andmovable contact 429 of key 522 is grounded at both ends.

Relay 4 l Sis also provided with a contact tongue 4 32' whichco-operates with a back contact only.

The back contact-is connected to grounded bat- 44-8 is connected toground.

Relay 534 has a. single contact tongue 43'! and front contact which isengaged by the contact tongue. Contact tongue. 3 3! is connected toground. The front contact with which contact tongue 43?; co-onerates is"connected to one te r minal of a lamp 438, the other terminal of whichis connected to grounded battery 439.

The operation of the subscribers stations A and B and of the centraloffice equipment has been described up to the point where repeater 353and operators set 365 have been. placed in condition to receivepermutation code signals from the operators set comprising transmitter 258 in Fig. '7 or from the subscribers transmitter stations A or B, thisbeing accomplished by insertion of plug l into jack. Upon communicationto the operators set as! of the identity of the permutation code stationwith which station A or B desires to communicate and, it being. assumedthat such station is the subscribers station C. the operator insertsplug 393 .into jack 4H. Plug tip- 382 engages jack spring 4.!2 andextends the communication circuit to the front contact with whichcontact tongue are of relay 4E3 co-operates. Plug sleeve 4&2 engagesjack bushing 414 and places reiay M3 in series with relay dill, whereupon. both relays become energized. Relay ifil removes local batteryfrom plug tip 352 and prepares locking circuit for double wound relay398.

Relay 413 moves itscontact tongue H6 into engagement with its fixedcontact, thus extending the communication circuit through one of thewindings of differential relay A8 and through conductor did to the openkey @223. The relay 4l3 also attracts its contact tongues it i and 32.The contact tongue 126 completes a circuit from ground through batteryM3, the upper winding of differential relay M8, front contact andcontact tongue -32 1, line conductor receivin selector magnet 52?, andtransmitter 328 at the subscribers station C to ground through the key422. Thus, a circuit is completed through the upper winding of relay M8and through the selector magnet 27 at subscribers station Since therelay M8 is adifferential relay, and only one of its windings is nowenergized, the contact tongue will be attracted to connect ground to oneend of the winding of relay 434 and also to the plug sleeve contactspring 436 of jack 4! G. Since the circuit from battery 4533 to theother end of the winding of relay 434 is open of relay 394 is completedand relay'te i attracts its contact tongues, thus completing theenergizing circuit for the double wound relay 3% which becomes energizedand completes its holding circuit. The relay 334 also connect lamp 391to ground so that the lamp becomes continuously illuminated.

The subscribers station C is provided with a ringer 44! connected acrossthe normally open key 422 and having in series therewith a condenser 442so that the ringer will be responsive to alternating current only.VVell-known means may be provided at the central ofiice for applyingalternating current between the line conductors M9 and sat for operatingringer ull to atract the attention of the subscriber at station 0 sothat he may place his printing telegraph apparatus in operatingcondition to receive a message. The subscriber does this by closing thekey 422. Movable contact 529 is thus disengaged from grounded fiXClcontact 4-3! and is engaged with contact 125. Also, a movable contact443 completes the circuit of motor 444 which is set in operation todrive the receiving printer represented by the selector magnet 5-21 andthe transmitter mechanism 428.

As the result of closure of the key 29, a communication circuit iscompleted from battery 423 through the upper winding of relay 4H3,contact tongue sac, line conductor 325, receiving selector magnet 21transmitter 4-28, movable contact 329 and fixed contact 42! of key 622,line conductor ile, lower winding of relay M8, contact tongue iiii,spring 512 of jack 3H, tip 392 of plug 333, winding of relay 356 ofrepeater 3%, and contact tongue 39B of relay 352 to ground. It will beobserved that the communication circuit includes both windings of therelay M8. Since this is a differential relay, it will release itscontact tongue 5-35 and the tongue will remain released as long as key622 is closed and plug 393 is in the jack 4i i, regardless of changes inthe line from marking to spacing or spacing to marking condition.

The release of contact tongue 235 results in the removal of groundconnection from relay 4% and tongues M6, 424, and 4232.

relay 4 .34.

relays 394 and 3S8, the latter remaining energized due to its holdingwinding. The release of the contact tongues of relay 39 3 will result inconnection of the source of interrupted current 399 to lamp through theattracted contact tongue of relay S98 and the released right-handcontact tongue of relay 394. This will indicate to the operator at thepermutation code switching portion of the central o-fiice, shown in Fig.8, that station C is in condition to receive a message. The operatorthereupon notifies the subscriber at station A by operation of theoperators receiving and transmitting set 35! that he may proceed withthe transmission of the message. The message will traverse the repeaterin Fig. '7 and the repeater 3'63 in Fig. 8 in reaching the subscribersstation C and will be transmitted back to subscribers station A for homerecord purposes as a facsimile mess-age, conversion taking place in thetranslator 273.

When the subscriber at station A has completed the transmission of themessage, he opens his key 2 i 5 and as previously described, lamp 229becomes illuminated due to removal of energizing current from one of thewindings of differential relay 2E8. Thereupon, the operator at thecombined permutation and code facsimile switching portion of the centralOffice withdraws the plugs 23.2 and 29!. The Withdrawal of plug 291results in de-energization of relay 339 and extinguishment' of lamp 353associated with jack 336. Thereupon, the operator at the permutationcode switching portion of the central ofiice, which is that shown inFig. 8, withdraws the plugs 35! and 393 from the jacks 335 and i! 1,respectively. The circuit of the relays 363 and dill are thusinterrupted and these relays release the holding circuits of the doublewound relays 38| and 398, respectively. Also the circuit of relay 373 iinterrupted due to the withdrawal of plug 35L The circuits of lamps 39'!and 3'18 are thus interrupted and the lamps are extinguished.

The withdrawal of plug 393 from jack 4! l opens the circuit of relay M3which releases its contact The contact tongue i-it upon release movesinto connection with the battery 4 i 1 and the contact tongue 424 movesout of connection with the upper winding of differential relay 4 I 8,and into connection with ground. Thus, a circuit is completed frombattery 4|! through contact tongue H6, lower winding of relay 4E8, lineconductor 4!.1, closed key 422, transmitter 428, receiving selectormagnet 421, line conductor 42S, and contact tongue 424 of relay M3 toground. The lower winding of relay H8 is thus energized and since thecircuit of the upper winding is interrupted at the contact tongue 424,the relay will attract its contact tongue 35 to connect ground to oneend of the The other end of the winding of relay 434 will be connectedto battery 33 due to the release of the contact tongue 432 by relay 4|3.Thus, the relay 434 will become energized and will connect ground to itscontact tongue 431 to the lamp 438, thus completing the circuit of thelamp which will become illuminated. This will indicate to the operatorat the portion of the central ofiice, shown in Fig. 8, that thesubscriber at station 0 has not yet opened his key 422. If the lamp 438does not become extinguished within a reasonable time, the operator mayreinsert plug 3% into jack 4H and inquire as to whether the subscriberat station C desires to transmit a message. However, should thesubscriber at station C open the key 422 promptly upon the terminationof the received message, the lower winding of relay H8 will becomede-energized, the contact tongue 435 will be re1eased,'thusinterruptingthe circuit of relay 434 which will release its contacttongue 43.1 andextinguish lamp 438.

It may happen'that during reception of a message at station C thesubscriber may wish to interrupt the message being transmitted .to him,such as to enable him to transmit a question or comment concerning themessage, or a reply to a question contained therein. Also, he may desireto interrupt the message in order to transmit a message to anotherstation which will hecessitate the changing of connections at thecentral office to connect station C with the desired other station whichmay,'for example, be the station D.

The interruption of message reception at station C may be accomplishedby momentaryopening of key 422. Fixed contact 42! and the lower windingof differential relay 4T8 is thus disconnected from movable contact 429and the grounded fixed contact MI is contacted by the movable contact429, :thus causing the upper winding only of the relay 418 tobeenergized'and to attract contact tongue 435. Ground is thus connectedthrough jack spring 136 and plug ring 396 to relay-3534 which becomesenergized and attracts its right-hand contact tongue out ofengagementwith the contact to which the source of interrupted current399 is connectedand into engagement with a grounded contact, thuschanging lamp cs1 from intermittent illumination to momentary steadyillumination. This indicates to the operator at the central *office thatkey 422 has been opened whereupontthe operator actuates set 36 to makein-ju'iry of the subscriber at station C as to the reason for hisinterruption of the transmissionor the identity of the station withwhich he desires to communicate.

For purposes of illustration, it is convenient to assume that thesubscriber :at station desires :to communicate with station D. Theoperator at the central ofiice completes the connection by removing plug35] from jack 335 and inserting it into jack MH. This causes relays 3E8,373', and 38! at the central office to be energized in the same mannerthat re1a'ys'394, 398, and 191 were energized when plug 393 was iii--serted into jack 4! I, and causes relays H3 and the upper winding ofrelay NIB to be energized. The operator then applies ringing currentbetween the line conductors M19 and N26 to operate ringer 14$! for thepurpose of notifying the subscriber at station D 'to close his key M 22.Upon the closure of the key I422 relay [4T8 releases its contact tongue1435 due to the placing of its :two windings in series and relay '313 isreleased to cause its contact tongue 316 to move into its engagementwith its back contact, whereby lamp 318 is connected to the source ofinterrupted current 388 and will flash for the duration of thetransmission between stations C and D. From this it will be observedthat the source 'of interrupted current 388 which does not "becomeeffective at any time during communication between one of the combinedstations, such as A or B, with one of the permutation oodestations C MD,does become efiective during com munication between two permutation codestations, such as the stations C and D. a

It is also possible for a permutation code station, such as the stationD, to initiate communication with one of the combined stations, such asthe station B. The subscriber :at station D closes the key M22 whichcompletes the circuit of the motor MM and also completes a circuit fromthe battery it! 1 through the flower contact tongue of relay .t'dtlS,through the lower winding of relay 141%, conductor :i kifi, :key i222,transmitter i are, receiving selector magnet .l line conductor 11326.,land innermost upper contact tongue of relay It to ground. .Differentialrelay 141-3 having only one of its win ings :energized attracts its:contact tongue E1435 to .complete the circuit :of relay 165:4 wherebylamp [11'3315 illuminated. The lamp M338 serves ;as .a signal to theoperator to answer the station 113 by inserting either the plug 35! orthe plug .393 into 'jjaek idiLi, "the two plugs having identicalsupervisory circuits associated therewith. 1t will he assumed that theoperator :answers with the plug 33-3. Relays i394, 3928, and i areenergized, as also rrelay Edit, whereupon the lamp controlling' relayM534 is released "and relay 39 i is released to cause lamp Si-i1 to beiil'lumir'i'aited intermittently. NVhen :the operator hasa'scertaincdsfromtthesubscriber at station '1) the identity of thestation with which he Wishes to communicate, which will be assumed to bestation B, plug it! is inserted into ,jack 335, thus causing thesupervisory relays 3.76;, 3.58, and 331 to becomeienergized and alsothezrelaytfifi whereby lamp 353 is :steadily illuminated.

The .lamp 359 Jserves as a :s'ignal to :the operator who has thereceiver 125.9 to :answer the call available at :33], This isaccomplished 'by inserting plug 5232 into Jjack 3.3. whereupon thesupervisory zreiays 1262, 22:13, and 2%, associated with lplug 2232,operate and the operator's receiving printer, represented by the magnet2419, and the transmitter 1438 :are connected .to the permutation :codecommunication :circuit which has ibeen 'entended to plug 2.91.Theoperatorat the central-office of Fig. '7, upon being informed thatthe subscriber :at station 513 is the called subscribeninsehts plug'Z-Fii into jack i233. The supervisory -;ci:rcuits associated with theplug 29-! respond to the insertion of the plug into jack i235 :and thesupervisory circuits associated with the neck respond .in the samemanner :as :previously described for transmission of .a message fromstation .A to station .3. The permutation code signals repeated by therepeater in Fig. .7 from the signal transmitted from :station D willterminate :at the ground engaged by contact tongue x'lfitil ot-relay.362, due to the fact that relay 392 :does not remain energized becausethe contact tongue 1225 of differential irelay 12% at station B will beout of engagement with "its back :contact as a result of theenergization of the lower Winding only of "relay ii-iiil. Should thesubscriber :at station a? close his key liilfi, which he has .nooccasion to do unless he desires to :hrea'k in .on :the message beingtransmitted to him, zt'n'erelay 1218 will release its contact tongue andground connection will be :extended to the relay i362 to cause it to beenergized, thus attracting =its icontact tongue 131.9 and disconnectingground from the permutation code-signaling circuit at that point, theterminal of the ciroui't then being the ground at the translIlltCEl i il fi of su'bscr'ibers station E. Since here is no apparatus at thestation B responsiv'e to permutation code signals, those signals will 'have-no efiect at that point. Facsimile signals for actuating thefacsimile recorder i2lll will 'be generated in the photoelectric cell238 of the translator and will be impressed upon the conductor 28% andthe plug tip 292 from which point they will traverse the jack spring1264, telegraph line i253, and relay E282 terminating at the facsimilerecorder I25. The energization of relay 232 will cause the motor circuitto close and remain closed, thus causing the motor IZdl to be actuatedfor driving the facsimile recorder 9285.

When the subscriber at station D concludes the transmission of themessage, he opens the ey I 422. This opens the circuit of one of thewindings of the relay M98 which thus becomes unbalanced and attracts itscontact tongue M35, connecting ground through jack Hill to the windingof relay 3% which becomes energized and attracts its right-hand contactspring into engagement with the grounded front contact, thus causinglamp 331 to be illuminated steadily. Thereupon, the operator withdrawsplug 393 from jack 4H and withdraws plug 35l from jack 3%. All of thesupervisory relays associated with jack l4! 1, with plug 3:33, with plug35!, and with jack 336 become de-energized, whereupon lamp 353 will beextinguished. This is the signal to the operator at that portion of thecentral office, shown in Fig. 7, to withdraw plug 232 from jack 33! andto withdraw plug 29l from jack 12%. Upon the withdrawal of the plugs,all of the supervisory circuits, namely, those associated with the plug29!, the plug 232, and the jack 1286, return to normal.

Referring to Fig. 9, which shows a complete communication system thatmight be used in an industrial organization or hotel between the Variousdepartments thereof, or in a police intercommunication and broadcastsystem involving fixed and mobile stationathe reference numeral 56!designates a keyboard transmitter at each of the fixed stations E, F,and G. Keyboard transmitter Sfil may be of very simple form, such as theone disclosed in Patent 1,135,613 granted April 13, 1915, to L. M.Potts, having no transmitting distributor, but having merelytransmitting contacts to be closed substantially simultaneously inpermutational code combinations under control of a keyboard mechanism.The keyboard is provided with a lock lever 562 controlled by a magnet553 for locking the keyboard when a key lever has been depressed. Thetransmitting contacts are connected to conductors contained in a cable535. The cable terminates in a central ofiice H where the transmittingcontact conductors of all of the cables 56 are connected to bus bars orother common conductors 565.

The common conductors 586 are connected to the individual selectormagnets 56? of a translator mechanism which may be similar to oridentical with that shown in Figs. 1 to 3, the magnets 55? correspondingto the magnets El of Figs. 1 to 3. The armatures 568 of the magnets Eitlare arranged to operate the slides 55!! which control the shutter slidesEli and also effect tripping of a clutch, such as that shown in Figs. 1and 3, to impart rotation to the scanning drum. Through the rotation ofthe'scanning drum, signals are generated in photoelectric cell 512,which signals are amplified by amplifier 513 and are transmitted byradio transmitter 514.

The facsimile translator shown in Fig. 9 is provided with a pair ofnormally open contacts 576 that are closable by a cam operated lever'11.

Lever 51"! may be operated by a cam (not shown) driven along with thescanning cylin der and arranged to close the contacts at the beginningof rotation and to permit them to open near the end of the cycle. One ofthe contacts is connected to battery and the other is connected to aseventh conductor contained in each of the cables 554. At the stationsE, F, and G, the seventh conductors are individually connected to thekeyboard lock controlling magnets 563.

Each of the stations E, F, and G is provided with a radio receiver 5'58for receiving facsimile telegraph signals transmitted by the transmitter514, and the output of the radio receiver is connected to the signalresponsive magnet 5'59 of a facsimile printer 58% for recordingfacsimile messages received by the radio receiver '518. There may alsobe stations, such as the station J, from which there is no occasion totransmit messages, which are provided only with a radio receiver 578and. a facsimile recorder 58!. The station J may, for example, be apolice motor vehicle equipped only for one-way communication, as is acommon custom; namely, for the reception of information or instructions.

In the system shown in Fig. 9, message transmission from any of thestations E, F, or G may be efiected by depressing the keys to controlthe permutative closure of contacts 56!. Upon the depression of any key,certain of the contacts 55| at that station will be closed to completethe circuits of corresponding ones of the magnets 561. This will result,a disclosed in Figs. 1 to 3, in the generation of facsimile signals atthe photoelectric cell which will be amplified at 573 and broadcast bytransmitter 574. At the beginning of the generation of the facsimilesignal, contacts 516 are closed, thus completing the circuits of magnets563 at all of the stations E, F, and G, whereby the magnets becomeenergized and the locks 562 are operated to look all of the keyboards.

As the facsimile signal corresponding to the permutation code istransmitted by radio transmitter 574, it is received by the radioreceivers 518 at stations E, F, G, and J and is recorded on thefacsimile printers iiSi. Toward the end of the facsimile signal contacts5'36 are opened and the magnets are released, whereby locks 562 aredisabled and a key may be depressed at any of the keyboards. Byproviding for the looking of all of the keyboards, one keyboard may notbe operated to interfere with the registering, upon magnets 56?, or acode combination initiated at another keyboard.

Another communication system employing apparatus according to thepresent invention is shown in Fig. 10. Referring to that figure, thereference numeral tel designates a keyboard transmitter which may be ofthe type shown in Patent No. 1,595,472 granted August 10, 1926, to H. L.Krum, which may be considered the equivalent of the transmitters shownin Figs. 7 and 8 having transmitting contacts 632 connected to groundand to a communication conductor 8%. The keyboard transmitter 68!, and afacsimile recorder 6 3 5 which may be similar to the facsimile recorders2M and i, shown in Fig. '7, make up a subscribers station, such as thestation K. The facsimile recorder 664 is connected to one end of acommunication conductor 601.

Other subscribers stations L and M are similarly provided with keyboardtransmitters 6M and facsimile recorders 6%.

Each of the conductors 663 is connected to one asso /gees terminalof anindividual. line relay 668 at a' central oifice station N and theother-terminal of the winding of each relay 608 is connected to battery559. A series circuit beginning atground at the cen ral onice station Nincludes the line" relay contacts EH of the line relays 658, and theselector magnet M201 a signal translator G l-3' which may be similar tothat shown in Figs. 4 to 6, inclusive, theseries circuit'then extendingfrom the selector magnet 512 to battery 689. The photoelectric cell 6Mcorresponds to the cell 32 in Fig. i and generates facsimile signalscorrespondin to permutation Code signals impressed upon theselectormagnet 652. .The facsimile signals generated in th cell 6&4 areamplified in amplifier M5 and are applied tothe communication conductorstd'l over which they are transmitted to the'facsimile recorders at'thestations Ii, L, and M.

Upon the operation of an one of the keyboard transmitters at stationsKL, and M, its

transmitting contacts 6&2 are operated in accordance with permutationcode combinations, and the signals are repeated by the line relays 568to control correspondingly the circuit of the selector magnet hi2 of thetranslator 613. The facsimile signals are generated at GM and aretransmitted over the conductors 5G! to the station which originated themessage to provide a home record and also to all Of the other stationsconnected to central'oflice station N. Thus, any one of the stations K,L, and M may communicate With each of the other stations in the system.As distinguished from the communication System shown in Fig. 9, thesystem shown in Fig. 10 involves metallic conductors throughout forinterconnecting the several stations and is particularly applicable toindustrial installations, hotels, and other business organizations whereit is desirable to provide intercommunication' between several locationswith the recording of all transmitted material at all stations;

Although certain specific embodiments of the invention have been shownand described herein, it is to be understood that the invention is notlimited to such specific embodiments but is capable of modification andrearrangement without departing from the spirit ofthe invention andwithin the scope of the appended claims.

What is claimed is:

1. In a telegraph apparatus, a permutation code signal receivingmechanism, permutation members positionable by said signal receivingmechanism, permutationally apertured slides in dividually controlled bysaid permutation mem-,

2.111 a telegraph apparatus, a permutation code signal receivingmechanism, permutationally a ertured slides positionable by said signalreceivlng mechanism, a source of light and a photoelectric cellassociated with said slides, a rotatable cylinder associated with saidslides, said source of light and said photoelectric cell, said cylinderhaving circumferential rows of apertures arranged according to afacsimile signaling code, means for rotating said cylinder, and means operated by said signal receivin mechanism for controlling the connectionof said cylinder to said rotatin means.

3. In a telegraph apparatus, a code signal receiving mechanism, signalresponsive members positionable by said signal receiving mechanism,

4. In a telegraph apparatus, a code signal re-- ceiving mechanism,signal responsive members positionable by said signal receiving.mechanism, light shutter members individually controlled by said signalresponsive members, a source of'light and aphotoelectric cell associatedwith said light shutter members, a rotatable cylinder associated withsaid light shutter members, said source of light and said photoelectriccell, said cylinder having circumferential rows of apertures are rangedaccording to a facsimile signaling code, means for rotating saidcylinder, and .meansope-n atedby said signal receiving mechanism for controlling the connection of said cylinder to said rotating means. r

5. In atelegraph apparatus, a code signal re ceiving mechanism,signalresponsive members positionable by said signal receivingmechanism, light shutter members individually controlled by said signalresponsive members, a source of li ht andv a light sensitive impulsegenerator associated with said light shutter members, a rotatablecylinder associated with said light shutter mem, bers, said source oflight and said light sensitive impulse generator, said cylinder havingcircume ferential rows of apertures arranged according to a facsimilesignaling code, means for rotating said cylinder, and :means operated bysaid signal receiving mechanism for controlling the connec tion of saidcylinder to said rotating means.

6. In a telegraph apparatus, a code signal re: ceiving mechanism, signalresponsive members positionable bysaid signal receiving mechanism, lightshutter members individually controlled by j said signal responsivemembers, a source of light and a light sensitive impulse generatorassociated with said lightshutter members, a rotatable scanning memberassociated with said light shutter members, said source of light andsaid light sensitive impulse generator, means for rotating said scanningmember, and means operated by said signal receiving mechanism forcontrolling the connection or said scanning member to said rotatingmeans. J i s 7. In a telegraph apparatusapluralityof signal responsiveelectromagnets, a light shutter member individual to and operable byeach of said electromagnets, said light shutter members being aperturedto establish variou single light paths according to the energization ofsaid electromagnets, a rotatable member having signal combinations oflight blocking and transmitting areas in registry with the light pathpositions, a source of light and alight sensitive impulse generatorassociated with said-lightshutter members and said rotatable member,means for driving said rotatable member, and means actuated by any ofsaid electromagnets upon the energi-

